In the related art, an embedded-type luminaire such as a downlight is installed by embedding a body part of a luminaire body thereof in an embedding hole provided on a ceiling panel or the like. The body part of the luminaire body is often formed cylindrically with the same diameter. A socket is arranged in an upper part within the body part, and a light source that is removably loaded in this socket is housed within the body part.
The embedded-type luminaire is not required to have high radiation performance if the light source is an incandescent bulb. However, particularly in the case of a lamp unit using an LED element, the luminaire needs to secure sufficient radiation performance in order to restrain temperature rise in the LED element. Moreover, simply adding a radiating structure to the luminaire body to secure radiation performance of the luminaire tends to result in a complex assembly structure and may lower assemblability.
An object of some aspects of the invention is to provide a luminaire that can secure radiation performance and also can improve assemblability.